Means for keeping vapor-converters alive.



P. H. THOMAS.

MEANSTOR KEEPING VAPOR. CONVERTERS ALIVE.

APPLICATION FILED DEC. 24, 1903.

Patented Sept. 15, 1914.

Q/Vttmcoow UNITED srA Es PATENT OFFICE.

PERCY" HI THOMAS, OF EAST ORANGE, NEW JERSEY, ASSIGNOR, BY MESNE ASSIGN- ME NTS, TO COOPER HEWITT ELECTRIC COMPANY, OF HOBOKEN, NEW JERSEY, A.

' CORPORATION OF NEW JERSEY.

MEANS FOR KEEPING VAPOR-CONVERTERS ALIVE.

To all tvhom it may concern:

Be it known that I, PERCY H. THOMAS, a

citizen of the, United States, and resident of East Orange, county of Essex, State of New Jersey, have invented certain new and useful Improvements in Means for Keeping Vapor-Converters Alive, of which the following is a specification.

In operating direct current work 011 uits through vapor converters from altern ting current. sources, where it is necessary to keep the converter 'ahve, t has been cus-' tomary at times to provide an inductive shunt and to rely upon the discharge from the inductive device for bridging over the zero point of the alternating current to the described invention is a system by which the keeping alive function is accomplished in such a manner as to eliminate this and other disadvantages andlto have certain peculiar characteristics of its own.

The invention will be understood from the description given in connection with the drawings.

My invention is illustrated in the accompartying drawing which is a diagram of a system of circuits adapted to contribute to the carrying out of my invention, the vapor converter being shown in section. I

In the drawing, 1 is a vapor converter havin a negative electrode, 2, of mercury or other suitable conducting fluid, two main positive electrodes, 3 and 4:, and two supplemental positive electrodes,'5 and-6. The

two main positive electrodes 3 and 4 are connected to theterminals-of an alternating current source and the negative electrode is connected through; a suitable load, such as a storage battery, 8, with the neutral or other intermediate point, 9, of the said source. This source may be a transformer, the primary, 7, of which is connected to any suitable alternating current generator, and the secondary, 77, of whichis a-direct current .source of supply for the circuits herein described. Between the leads, 10 and 11, (running respectively from the opposite terminals of the source to the main positive Specification of Letters Patent.

Application filed December 24, 1903.

Pate11ted S ept.15, 1914. Serial No. 186,489.

electrodes, 3 and 4c) and the lead from the negative electrode 2, are interposed, on the one hand, a resistance, 12, and an inductance, 13, and on the other hand, a resistance, 14, and an inductance, 15. From a point between the resistance 12 and the inductance 13, a conductor 16 is led off and connected with the supplementary positive electrode 5; and similarly from a point between the resistance 14: and inductance 15, a conductor,

17, is led off and connected with the supplemental positive electrode 6. The operation of this arrangement of circuits is as follows: During one alternation or phase of the current, energy is transmitted by way of the positive electrode 3 through the negative electrode 2 and the load 8 back to the supply through the neutral wire to the point 9. During this time the negative electrode 2 and the positive electrode 4 are affected by nearly the full potential of the supply, which will cause an increasing current to flow through the choke coil 15 and resistance 14 in the direction of the arrow 20, the direction of the electro-motive-force produced by the choke coil being the same. As, however, the electro-mctive=force of the supply falls there finally comes a zero point in the current delivered through the positive electrode 3 and a tendency of the current through the choke coil 15 and the resistance 'lt'to diminish. This causes a reversal of the direction of the electro-motive-force generated in the coil 15, which reversal results in the well known tendency of inductances to continue the flow of current in 'the. original direction in the inductance finding its easiest path through the .supplemental electrode 6 to the negative electrode 2. If the path be properly proportioned, before the energy of the choke coil 15 is exhausted the positive electrode 4 will have begun to supply. current to the negative electrode 2 and the work circuit 8 and the several cycles of operation will be repeated through the choke coil 13, the resistance 12 and the electrodes 5. and 3, the direction of flow through the said choke coil and resistance being indicated by the arrow 21.

In this arrangement :of the circuits, the storage battery or other source of counterelectro-rnctive-force can never cause dis-. turbance to the passage of the choke coil currents through their proper paths, by' reason of the fact that such coils during their nitude.

That there may be no possible misunderstanding of the operation of the device herein described, the action may be set forth in the few following paragraphs.

In this system the work currents are fed alternately from the two main anodes 3 and 4 through the work circuit 8. These impulses keep the device alive except for the zero points between them. There is required in addition merely impulses bridging these zero periods which impulses are supplied alternately by the supplemental anodes 5 and 6. This impulse from a supplemental anode comes from the choke coilassociated therewith and is derived from energy stored in that choke coil during the prior alternation. The discharge of this energy takes place as follows: While a working impulse is passing from the main anode 3 to the work circuit, a small current passes simultaneously by way of the coil 15 and resistance 14 to the line wire 11. It is clear that the potential of the cathode 2 during this period is practically that of the anode 3 except for the drop of voltage in the rectifier itself which is but a fewvolts. Therefore, the voltage impressed upon the inductance 15 and the resistance 14 is for the time being substantially the full voltage of both halves of the transformer secondary77. Energy is thus stored at a relatively rapid rate. As the voltage of the supply drops to zero the impulse in the work circuit ceases and the storing of energy in the coil 15-ceases. The energy previously stored, however, now provides a sufiicient electro-motive-force to maintain the flow of current in this coil 15 at its previously established value except for the wearing away of energy due to the current flow. The easiest path for this current, which is supported by the coil 15, is

through the supplemental anode and the cathode 2; Since, now, energy was stored at a very high rate under the full transformer voltage, it will be worn away at a relatively low rate since the discharge path requires but a few volts to maintain the current. Therefore, the discharge of the coil 15 may continue not-only over the first zero point but through the next alternation and the next zero point until charging in this coil is again resumed in the next cycle. It is possible, however, that the stored energy may run out before the recharging period recurs, that is, it may run out while the main anode 4 is supplying work current to the cathode 2. During this period, obviously, the cathode 2 is at approximately the voltage of the main anode 4 except for the few volts lost in the rectifier. That is, the voltmust be overcome before any energy can be usefully stored in the coil 15 from the side current coming from the main anode 3.

Such backward current would be very small in any case. A similar action takes place in connection with the inductance 13 but a half cycle later in time.

It is thus seen that the current in each of the coils 13 and 15'is practically unidirectional always flowing (with the possible momentary reversal) from the coil to the supplemental anode. While it is true that the coils 13 and 15 with the resistance 12 and 14 constitute a shunt on the transformer supply the current flow from these coils is entirel dominated by the varying of the potentlal of the anode 3 in one alternation to that of the anode 1 in the next alternation, in such a way that during one set of waves practically all the "oltage is impressed upon one of the coils and during the other trainof waves practically all the voltage is impressed upon the other coil,

with the result that there is on the average a strong unidirectional voltage on each of the coils in opposite directions in the two .coils. WVere no vapor rectifier present there a negative electrode, one or more main positive electrodes and one ormore supplemental positive electrodes, the method of supplying current through the converter from an alternating current source at the natural zero point in the supply, which consists in accumulating an inductive charge during one alternation in shunt to the converter and discharging the energy at the appropriate time through the supplemental electrode and the negative electrode.

In a circuit containing a apor converter requiring to be kept alive and having a negative electrode, one or more main positive electrodes and one or more supplemental positive electrodes, the method of supplying current through the converter from an alternating current source at the natural zero point in the supply, which consists in cansing current to pass through a path including a main positive electrode and the negative electrode during one alternation, accumulating an inductive charge during the same al ternation in shunt to the converter, and-discomprising a source of alternating current supply, a direct current work circuit, and an interposed vapor converter, the method or kee ing' the converter alive and maintaining a co tinu-o'us supply of current in the work circuit, which consists in applying to the converter alternately from-1oppos1tetermn nals' of the supply source impulses of likephase representing a, fractional part of the electro-j-motive-force of the supply, and, at times ofthe natural zero for they said impulses, applying to the converter impulses accumulated substantially from j the entire 'electro motive-force of the supply. i

4.111 a system of electrical QISt IIbHtIOD, comprising a source of alternating current supply, a direct current Work circuit including' a source of counter-electroemotive-force,

and an interposed vapor converter, the method of keeping theconverter alive and maintaining alcontinuous supply of current in the work. circuit, which consists in applying'to the converter alternately from 9ppositejter'minals of the supply source 1m ulses ,of like ph aserepresentm-g a fractiona part of the electro-motive-force of the supply, simultaneously accumulating an inductive charge under the influence of substantially the entire electro-motive-force of the sup ply, at timesofthe'naturagizei'o for the said. impulses, emptying the sai (ob arge through the converter.

' 5. In a system of electrical distribution, comprising a sfiurce'of alternating current supply, a direct current work circuit including a source of counter-electro-motive torce, and an interposed vapor, converter, the

' method of keeping the converter alive and maintaining a continuous supply of current in the work circuit, which consists in applying to the converter alternately from opposite terminals of the supply source, impulses of like phase representing a fractional part of the electro-motive-force of the supply, simultaneously accumulating an inductive charge under the influence of substantially the entire electro-motive-force of the supply and, at.tim;a's of the natural zero for the said impulses, emptying the said charge through the converter, and simultaneously afl'ecting the discharge current by a resistance preventing its flow through the wrong path.

6. The method of operating a vapor rectifi'er requiring continuous flow of current therein for purposes of excitation which consists in passing normal Work currents through the rectifier and through the receiving circuit, with drawing additional current through the rectifier around the Work cirutilizing this How of energy to maintain a flow of current in the rectifier during inter vals when no current is flowing therethrough to the work circuit.

\nating current is rectified by means of the rectifier requiring continuous excitation, the method of securing'a free and unimpeded flow of useful current through the rectifier to its receiving circuit which consists in maintaining excitation of the rectifier during times when no current is fiowing' to the rectified circuit by means of'energy obtained from the supply stored momentarily and deriving said energy withoutpermitting it to traverse the receiving circuit.

8. The method of rendering free and unimpeded the flow of current in a receiving which consists in deriving useful currents from a suitable sourcethrough the rectifier and obtaining exciting current from the circuit independent of the receiving circuit.

9. The method of operating a rectifier requiring continuous excitation which consists in deriving useful currents and securing exciting current from the supply through the rectifier independently of the useful currents so that an interruption in the useful currents will not cause an interruption of the exciting current.

10. ha system of electrical distribution, a source of alternating current supply, a direct current work circuit, including a source Of counter electro-motive-force, and an interposed vapor converterlthe said converter being providediwith two main positive electrodes, two supplemental positive electrodes, and a common negative electrode, in combination with a connection from the negative supply, leads from the terminals of the supply to the respective iiain positive electrodes, shunt connections from the said leads to the negative electrode, such shunt connections, eaclr including an inductance, and leads from the said shunt connections to the respective supplemental positive electrodes.

11. In a system of electrical distribution, a source of alternating current supply, a direct current worlgcircuit, including a source of counter electro n ptive force, an, intertrodes, two supplemental ositive electrodes, and a common'negative e ectrode, incombination with ,aconnecti'on. from the negative electrode to an intermediate oint of the sup- .to the respective main positive electrodes,

cuit, storing from this latter current and 7. In a system of circuits in which altercircuit of a rectifier requiring excitation e ectrode to an intermediate point of the posed vapor converter, the said converter being provided with two main positive elecply, leads from, the termina s (if-the supply v shunt connections from-the said leads to the' negative electrode, such shunt connections 1 each includin aninductance and a resistance, and lea s from points between the sald Fr inductances and resistances to the respective;

supplemental positive electrodes,

12. In'a systemof electrical distribution, a source of alternating current .supply,a direct current work circuit, an interposed va- 10 por converter, the said converter being pro-. vided with two mBIII pOSItIVG electrodes, two 7 tances and resistances to the respective sup-;

' plemental," positive electrodes, the inductances on each side bein located between the plcmental positive electrode and la. point of connection of the said shunt; to the negative electrode. a

13. The combination of a source of current, a vapor electric device connected thereode, a pluralityot direct-current circuits connected tosaid fcathode and receiving energy from said shunt translating devices in one of said circuits, and a reactance in another of said circuits to maintain said rectifier active.

-14. The combinationof vapor rectifier, v

a source of energy therefor, a consumption circuit connected to said rectifier and traversed by unidirectional current,.and. reactances eoimectedfin shunt with saidrectifier to maintain a current flow .therethrou h. I

115. The combination ofpa vapor e ectric device having a cathode and a plurality of anodes, means for supplying current-t0 said ,anodes, a plurality of auxiliary 'anothes, means for maintaining arcs between said auxiliary anodes, and said cathode, said means including rcactance devices in shunt with said arcs. v '16. The combination with a mercury vapor rectifier, an alternating'supply, and a direct-current work circuit therefor,-of enener storin devices in shunt to the rectifier together with means for causing the point of connection of t e shunt to the supto having a'plurality of anodes and a cathv storing devices and means for charging direct current work-'icircuit therefor, of re? actance and means for" charging saidreapt' ance in shunt to the rectifier together-with means for causing the discharge of said-re actance through a short .circuit including said rectifier. a

.18. The combination with a mercury vagor rectifier, an alternating supply, and a irect current work circuit therefor, of a plurality of reactance's andmeans whereby said reactances are charged from substantiwlly the full supply voltage and discharged substantially through a short circuit including saidrectifier.-

19. The combination with a mercu vapor rectifier, an alternating supply, sai rectifierbeing' connected by twoanodes to the terminals of the supply, anda direct current receiving circuit, of inductances supplied with current across said supply and a connection includin said work circuit between the common lea of said inductances and an intermediate point of said source, the cathode of said rectifier being connected to said common lead.

por rectifier, an alternating su ply, and a direct current work circuit therefonof means for maintaining cpntinuity of operation by utilizin energy stored from certain portions 0 the supply winding at times when such supply vportions are not for the moment pas'sin current directly to the work circuit, '21. he combination with a mercury vs.-

20., The combination with a mercury va per rectifier, an alternating supply, and a1 direct current work circuit therefor, of means "for passing current through said work circuit, means for deriving from said source ad: ditional current, inductances traversed by said additional current and circuits for per-I mitting the discharge .of said inductances with a path other thanthe work circuit.

4 22. An exciting circuit for a vapor rectifier fed from an alternating current source, and supplying direct current to a suitable work circuit, com rising means, for deriving a pluralityof impulses from said'source through said rectifier independently of said work circuit, means for storlngenergy from such impulses and circuits whereby such en-- ergy may be discharged through the rectifier during gaps between said first "named impulses and current flow is continuously maintained in the rectifier independent of the current flowin to the work circuit. Signed 'at fiew York, in .the county of New York, and State of ,New York, this 16th day of December, A. D. 1903. V

I I PERCY H. THOMAS; Vitnesses:

GEORGE H. s'ronamnon. 

